From ed40a59c44459ffb3f0d8184a92c660f5bc70114 Mon Sep 17 00:00:00 2001
From: Gregor Schneider <grschneider@gmail.com>
Date: Fri, 10 Apr 2009 20:39:05 +0000
Subject: [PATCH 1/1] Update LineDDA implementation, -13 gdi32 path tests

svn path=/trunk/; revision=40448
---
 reactos/dll/win32/gdi32/objects/linedda.c | 117 +++++++++-------------
 1 file changed, 46 insertions(+), 71 deletions(-)

diff --git a/reactos/dll/win32/gdi32/objects/linedda.c b/reactos/dll/win32/gdi32/objects/linedda.c
index 2c5b51d797d..f6312bbdff7 100644
--- a/reactos/dll/win32/gdi32/objects/linedda.c
+++ b/reactos/dll/win32/gdi32/objects/linedda.c
@@ -1,7 +1,9 @@
 /*
- * LineDDA
+ * GDI drawing functions.
  *
- * Copyright 1993 Bob Amstadt
+ * Copyright 1993, 1994 Alexandre Julliard
+ * Copyright 1997 Bertho A. Stultiens
+ *           1999 Huw D M Davies
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -15,15 +17,15 @@
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 /*
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS GDI32
  * PURPOSE:          LineDDA Function
- * FILE:             lib/gdi32/objects/linedda.c
+ * FILE:             dll/win32/gdi32/objects/linedda.c
  * PROGRAMER:        Steven Edwards
- * REVISION HISTORY: 2003/11/15 sedwards Created
+ * REVISION HISTORY: 2003/11/15 sedwards Created, 2009/04 gschneider Updated
  * NOTES:            Adapted from Wine
  */
 
@@ -36,7 +38,7 @@
  * @implemented
  */
 BOOL WINAPI LineDDA(INT nXStart, INT nYStart, INT nXEnd, INT nYEnd,
-                        LINEDDAPROC lpLineFunc, LPARAM lpData )
+                    LINEDDAPROC callback, LPARAM lParam )
 {
     INT xadd = 1, yadd = 1;
     INT err,erradd;
@@ -44,73 +46,46 @@ BOOL WINAPI LineDDA(INT nXStart, INT nYStart, INT nXEnd, INT nYEnd,
     INT dx = nXEnd - nXStart;
     INT dy = nYEnd - nYStart;
 
-	// optimized for vertical and horizontal lines so we avoid unnecessary math
-	if(nXStart == nXEnd)
-	{
-	  // vertical line - use dx,dy as temp variables so we don't waste stack space
-	  if(nYStart < nYEnd)
-	  {
-	    dx = nYStart;
-	    dy = nYEnd;
-	  } else {
-	    dx = nYEnd;
-	    dy = nYStart;
-	  }
-	  for(cnt = dx; cnt <= dy; cnt++)
-	  {
-	   lpLineFunc(nXStart,cnt,lpData);
-	  }
-	  return TRUE;
-	}
-
-	if(nYStart == nYEnd)
-	{
-	  // horizontal line - use dx,dy as temp variables so we don't waste stack space
-	  if(nXStart < nXEnd)
-	  {
-	    dx = nXStart;
-	    dy = nXEnd;
-	  } else {
-	    dx = nXEnd;
-	    dy = nXStart;
-	  }
-	  for(cnt = dx; cnt <= dy; cnt++)
-	  {
-	   lpLineFunc(cnt, nYStart,lpData);
-	  }
-	  return TRUE;
-	}
-	// end of H/V line code
-    if (dx < 0)  {
-      dx = -dx; xadd = -1;
+    if (dx < 0)
+    {
+        dx = -dx;
+        xadd = -1;
+    }
+    if (dy < 0)
+    {
+        dy = -dy;
+        yadd = -1;
     }
-    if (dy < 0)  {
-      dy = -dy; yadd = -1;
+    if (dx > dy)  /* line is "more horizontal" */
+    {
+        err = 2*dy - dx; erradd = 2*dy - 2*dx;
+        for(cnt = 0;cnt < dx; cnt++)
+        {
+            callback(nXStart,nYStart,lParam);
+            if (err > 0)
+            {
+                nYStart += yadd;
+                err += erradd;
+            }
+            else err += 2*dy;
+            nXStart += xadd;
+        }
     }
-    if (dx > dy) { /* line is "more horizontal" */
-      err = 2*dy - dx; erradd = 2*dy - 2*dx;
-      for(cnt = 0;cnt <= dx; cnt++) {
-        lpLineFunc(nXStart,nYStart,lpData);
-	if (err > 0) {
-	  nYStart += yadd;
-	  err += erradd;
-	} else  {
-	  err += 2*dy;
-	}
-	nXStart += xadd;
-      }
-    } else  { /* line is "more vertical" */
-      err = 2*dx - dy; erradd = 2*dx - 2*dy;
-      for(cnt = 0;cnt <= dy; cnt++) {
-	lpLineFunc(nXStart,nYStart,lpData);
-	if (err > 0) {
-	  nXStart += xadd;
-	  err += erradd;
-	} else  {
-	  err += 2*dx;
-	}
-	nYStart += yadd;
-      }
+    else   /* line is "more vertical" */
+    {
+        err = 2*dx - dy; erradd = 2*dx - 2*dy;
+        for(cnt = 0;cnt < dy; cnt++)
+        {
+            callback(nXStart,nYStart,lParam);
+            if (err > 0)
+            {
+                nXStart += xadd;
+                err += erradd;
+            }
+            else err += 2*dx;
+            nYStart += yadd;
+        }
     }
     return TRUE;
 }
+
-- 
2.17.1